RTA Mic's

[alex_kyuss]

Hi All, I no this has been gone over abit, but I havn't found the answers I am looking for.

I am looking for a reference mic. I have been looking at the Audix TR40A and I was woundering what people thought about it and if there was a better mic for around that money out there?

cheers all and a happy christmas

[Gareth Owen]

Behringer make the ECM8000 RTA Mic which is extremely good for the money.

[Simon Lewis]

Alex,

 

You will find a fairly good discussion of reference mics on the Smaart forum (EAW.com). The Behringer mic has been shown to exhibit a pretty flat response, and it's worth having anyway for those occasions when the mic might get damaged or stolen. The Audix mic is pretty good, but then there's a jump to the Earthworks and then again to the Bruel & Kjaar.

 

I believe Superlux make a cheap measurement mic, but it's not showing on the usual UK sites.

Other potential candidates are NTI (the battery powered MiniSPL is about £200 + VAT)

I use an MB measurement mic, but it's about £290 + VAT.

 

You mention RTA in your title.... if you look at past BR discussions you will see why many would suggest that it's not a good technique. Smaart, EASERA, Spectrafoo etc. can do a much better, more accurate job.

 

If you want to do some Smaart training, the orginal Siasoft guys have left EAW and have their own company. They're ruinning a training course in Manchester mid January. PM if you want details.

 

Simon

[TimmyP1955]

The Behringer is said to be pretty good, save for the top octave or so.

 

The Audix is fine.

 

The US Superlux distributor stopped selling the 99 measurement mic owing to (he says) very poor QC (QA). (He still sells the rest of the line.)

 

Everything else I'm aware of is MUCH more expensive than the Audix.

[tall_phill]

Hi All, I no this has been gone over abit, but I havn't found the answers I am looking for.

I am looking for a reference mic. I have been looking at the Audix TR40A and I was woundering what people thought about it and if there was a better mic for around that money out there?

cheers all and a happy christmas

 

I would 2nd what Simon said regarding measurement tools. A dual FFT measurement system is a much more usefull tool than an RTA. I would also add that to make to most of it (be it Smaart, EASERA, SIM3, et al) a serious effort needs to be made to educate ones self about how to interpret the data. Learning how to operate the tools is for the most part, easy as pie, it's the interpretation which is the tricky bit.

 

There are a handful of places that offer training in these tools. All the ones I know are application specific. The courses I have attended (Smaart & Sim3) are full of information that could be readily applied to to any other DualFFT system.

 

I use the DPA 4091 mics for system alignment. I believe they are more expensive than the Audix mics. They have many applications beyond system measurement which may make them excellent value for you. I have a pair on grand piano at the moment, and I can't think of a mic for equal money or less I would prefer. If I was going to buy my own dedicated measurement mics (the 4091s are owned by my employer) I would preference the 4090s simply so I don't need quite so much gain on my interface.

 

Of course, you may not want your reference mics going on stage...

[alex_kyuss]

Hi all,

Im sorry for my ignorance, I wrote my topic before I went to work. I didn't really mean "RTA" as I intend on getting a copy of smarrt. I no I can't afford a earth works mic but the DPA might be with in range, I was wondering what people thought the difference was between that and the audix? Another question I have is sound card choice? I was planning on getting a Digidesign Mbox mini. What do you use for aligning and measuring systems? My thoughts were that it had the best A/D converters for the price range.

 

Cheers for all your help?

pm sent Simon cheers

[Simon Lewis]

Alex,

 

I suspect that the DPA mics are quite a bit more expensive than the Earthworks! (I still call them B&K, even though that part of the firm became DPA some years ago).

If you decide to buy Smaart, hold off untill the training day... The last one I went on had a special offer for Smaart. You can download a 30 day trial from EAW.com to try out anyway.

Regarding a USB soundcard, have a look at the Smaart forum - (EAW again). The key issues are that there is a low noise floor, balanced input, phantom and reasonable correlation between the two channels, since Smaart makes a transfer function between the two channels. Most reasonable sound cards will do this, but in the past some have thrown up timing errors.

 

One other thing... although it shouldn't be a problem with the mics mentioned, it does help to have a capsule casing diameter of 0.5", as this is the most common size for pistonphone calibrators - should you want to calibrate the mic and interface so that the measurement software can take accurate SPL readings.

 

Simon

[RustyBrooks]

I'll second the Behringer, not had a problem with it over the last few years since my b and k got mashed and needed replacing, for the live music industry I work in, then I don't think the extra accuracy of a very expensive mic is necessary. If you're just starting with you're own gear save the extra cash for the pub, or a nice meal with the other half, unless you intend to do a lot of lab style measurements. I use a 58 for time alignment, though normally a radio, just really boring dragging a long mic cable around a gig for all the transitions, and very rarely put a reference mic into SMAART/EASRA.

[alex_kyuss]

Hi all,

Thank you all for your help. As for usb sound cards, is it a general problem with sending data through usb or is it a cheap sound card thing? And what sound cards would people suggest? Unfortunately I am far to poor at the moment to do anything (evening the training which I image would be the money better spent) this is merely some forward planning, unfortunately this isn't a wish list this is starting to become a important tool missing for my tool box.

Hope everyones enjoying the festive period I just finished for xmas!!!

[mattwire]

When I was a student, (ie had no money) I bought an Edirol UA25 soundcard (2 balanced ins with phantom, 2 balanced out) and a behringer ECM8000. I still use them now because I've never had any problems with them. Touring engineers seem quite happy when I use them as well.

[Simon Lewis]

A second vote for the Edirol UA25 - although it's up to the 25EX version now.

 

For practical purposes, there is often little measurable difference between the ECM8000 (probably free with three cornflake packet tops) and the DPA mics (requires surgical removal of arm and leg).

 

However, for inter unit matching, correct phase response, minimal long term drift and excellent serviceability, the better mics win everytime.

[tall_phill]

There is some good information from some very erudite folks over in this recent thread at PSW:

 

http://srforums.prosoundweb.com/index.php/...0586/0/0/13910/

[ChrisBogg]

Just as A Side step I have a behringer mic with smaart. can anyone tell me how important a pistonphone calibrator would be? I would like to take SPL readings as an option but I imagine these things are going to be expensive.

 

Does anyone have any opinions are they worth wile having for day to day FFT use in a live situation or should I save my money?

 

Chris

[Simon Lewis]

Chris,

 

Smaart (in magnitude mode) compares the two sound card channel inputs (usually reference & measurement) so calibrating the mic isn't necessary. If, in RTA mode, you want to measure SPL or Leq, then the mic does need calibrating. The instructions give you two options: 1) Use a pistonphone (calibrator) and tell Smaart what the reading is 2) Use a sound level meter and put your mic in the 'same soundfield' as the SPL meter's mic, then tell Smaart what the reading is.

 

1) is naturally better than 2. However, either method suffers from the problem that the calibration is lost just as soon as you touch the USB preamp gain knob....

 

If you want to take SPL readings, or more importantly, Leq and logging of SPL, then the calibrator is the best way forward (unless you buy a separate SLM). A good calibrator will be quite expensive, but CPC do a device for £79 + VAT (here). It's probably fine for non 'legal' requirements.

 

Simon

[ChrisBogg]

Thanks simon I will try the CPC one out.

 

 

Chris